The invention relates to a chuck device having a one-step lock and release mechanism for coupling a tool bit to a Jacobs-style of chuck of a power tool.
The American National Standards Institute has a specification for tool bits known as ANSI 107.4-1982 which generally refers to the driving and spindle ends of portable powered and hand-held machines. The tool bits referred to in accordance with the standard generally include a hexagonally-shaped shank having a circumferentially-extending groove surrounding the shank. The circumferentially-extending groove generally includes a curved bottom portion disposed between two shoulder portions. These tool bits are generally used for drilling, or are used for driving fasteners such as screws, nuts and bolts, and other workpieces requiring rotation of motion.
It is highly desirable to provide a chuck device which permits the quick and efficient replacement of tool bits as used with a power source such as a drill. Numerous examples of quick-release tool chucks are known, an example of which include U.S. Pat. No. 5,013,194.
During operation of the known quick-release chuck devices, a detent ball is normally positioned against the circumferentially-extending groove of the shank for affixing the tool bit within the bore of the quick-release chuck. A sleeve is generally urged into contact with the ball by a compression spring which establishes a locking engagement between the ball and the groove. The sleeve is generally limited in movement to one direction upon the quick-release chuck. A problem with the quick-release chuck devices involves the clenching or locking of a detent ball against the shoulder portions of the circumferentially-extending groove, which inhibits the retraction of the sleeve and the insertion of a tool bit into the quick-release chuck.